Applied Chemical Engineering

To improve the cathode electro-catalytic degradation performance of electrochemical advanced oxidation processes (EAOP), Pd metal and CeO_x co-modified Nano-graphite (Pd/CeO_x/Nano-G) composite was synthesized by chemical precipitation and reduction methods, and Pd/CeO_x/Nano-G cathode was prepared by a hot-pressing method. The as-prepared composite and electrode were characterized by X-ray photoelectron spectroscopy, X-ray diffraction and scanning electrons microscopy. Results revealed that the mix-crystal structural CeO_x (Ce₂O₃ and CeO₂) and Pd⁰ metal were formed. The cathode was applied for the electro-catalytic degradation of phenol wastewater. The degradation efficiency of phenol by Pd_1.0/CeO_x5.0/Nano-G cathode reached 99.6% within 120 min degradation, which were higher than that of CeO_x5.0/Nano-G and Nano-G cathodes. Both of the Pd metal and CeO_x could improve the O₂ reduction to H₂O₂ and promote the H₂O₂ dissociation to •OH for phenol oxidation. Additionally, the effects of electro-catalytic reaction parameters on the phenol degradation were investigated. The results indicated that Pd/CeO_x/Nano-G cathode would have promise for further practical application in organic wastewater treatment.

Electrochemical Cathode; Nano-graphite; CeOx; Pd Modification; Phenol Degradation

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